Transparency of hydrophobic acrylic intraocular lenses

Nagata et al.1 recently published an article detailing postoperative changes in the transparency of hydrophobic acrylic intraocular lenses (IOLs). There are several points in the article that merit comment. The first of these is the term whitening, a term used here and in a previous article by a coauthor of the present paper.2 We suggest this term is inappropriate as it is incorrectly applied to the surface scatter phenomenon observed in these papers. Nishihara et al.3 have pointed out that for slitlamp angles in which incident light is less than 30 degrees, the IOLs appear clear, even when this surface scatter is observed at higher incident angles. More important is the suggestion that the surface scatter phenomenon observed with the optical techniques in this current study1 is correlated with vision. There is no scientific or clinical basis for this comment. The results obtained in this study indicate that up to a year postoperatively, in the presence of the scatter phenomenon observed, there was no effect on vision. Mönestam and Behndig4 recently completed a large study of more than 100 patients 10 years after cataract surgery. The patients with the highest amount of total light scatter, measured with methods similar to those of Nagata et al., actually had slightly better mean high and low contrast acuity (though not significantly so) than patients with less light scatter. Miyata et al.5 showed similar results after 3 years. In short, there is no doubt that some change in surface scatter is observed in the current study when the IOLs are viewed with an oblique light source. However, calling this phenomenon whitening appears inappropriate based on the phenomenon’s dependence on incident light angle. In addition, suggesting a clinical impact is inconsistent with the body of clinical research available to date.